Drill press having pivotable table

ABSTRACT

A drill press including a vertically disposed support post and a pivot assembly supported upon the support post is disclosed. A table is supported on the pivot assembly. The pivot assembly is pivotable about a first substantially horizontal axis, with the table pivoting about the first horizontal axis jointly with the pivot assembly. The table also is pivotable relative to the pivot assembly about a second substantially horizontal axis. The pivot assembly also may be pivoted around a vertical axis defined by the post and may be raised and lowered along the vertical post. A clamp plate is adjustable secured to the table and a telescoping extension arm is fixably secured relative to the table by the clamp plate. A guide fence is slidably disposable along the upper surface of the table and may be secured at various locations. A clamp may be adjustably secured either directly to the table or to the guide fence to vertically clamp a workpiece on the table. The table also includes an opening and an inner table which is removably disposable and supported within the opening. A router may be removably secured to the lower surface of the table, with the router bit disposed generally beneath the drill chuck.

This application is a continuation of application Ser. No. 08/714,714,filed Sep. 16, 1996, now U.S. Pat. No. 5,765,273. This application isbased upon and claims priority under 35 U.S.C. §119 and 37 C.F.R. §1.78of copending U.S. provisional application Ser. No. 60/004,187, filed onSep. 22, 1996.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention is directed to a drill press having a pivotabletable, and in particular, a table which may pivot downwardly andforwardly towards the user around a first horizontal axis, from side toside around a second perpendicular horizontal axis and about a thirdvertical axis.

2. Description of the Prior Art

Conventional drill presses include a vertical post and a substantiallyhorizontally disposed workpiece support table supported between the topand bottom of the post. A head is supported at the top of the post, anda drill chuck extends downwardly from the head. The chuck holds a drillbit and is raised and lowered towards the table to thereby drill a holein the workpiece. The drill press also includes a motor which drives thechuck.

In some instances, it is desirable to drill holes through the workpieceat non-perpendicular angles to the upper surface. One way to achievenon-perpendicular drill holes is to provide a worktable which ispivotable about a horizontal axis extending through the table. Forexample, U.S. Pat. No. 1,564,876 to Mansfield discloses a boring machinein which the table may be pivoted left to right about a horizontal axiswhich intersects the vertical support post. However, in Mansfield thepivoting motion is limited to pivoting about one axis. No provision ismade for pivoting about a second horizontal axis. In addition, Mansfielddoes not disclose pivoting about a vertical axis such as would allowdrilling at different locations along the surface of the workpiecewithout moving it relative to the table.

SUMMARY OF THE INVENTION

The present invention is directed to an apparatus including a verticallydisposed support post and a pivot assembly supported upon the supportpost. A table is supported on the pivot assembly. The pivot assembly ispivotable about a first substantially horizontal axis, with the tablepivoting about the first horizontal axis jointly with the pivotassembly. The table also is pivotable relative to the pivot assemblyabout a second substantially horizontal axis.

In a further embodiment the second substantially horizontal axis issubstantially perpendicular to the first substantially horizontal axis.

In a further embodiment, the apparatus is a drill press and includes ahead supported by the post at a location above the table. A rotatablechuck is supported by the head. The drill press also includes a drivemechanism which rotates the chuck and a mechanism for raising andlowering the chuck relative to the table.

In a further embodiment, a pivot assembly is pivotable about a verticalaxis defined by a post and is movable in the vertical direction along apost. The pivot assembly is fixable in a selected vertical location tothereby allow the table to be pivoted about the vertical axis and fixedin a selected vertical location.

In a further embodiment, a clamp plate is adjustably secured to thetable and a telescoping extension arm is fixably securable relative tothe table by the clamp plate.

In a further embodiment the table has an upper surface and a guide fenceis slidably disposable along the upper surface at various locations.

In a further embodiment, the table has an upper surface with an opening,and an inner table is removably disposable and supported within theopening.

In a further embodiment the table has an upper surface including aplurality of holes. A clamp including a support arm is removablydisposable within the holes to removably secure the clamp to the table.

In a further embodiment a router is secured to the table, with therouter bit disposed generally beneath the drill chuck.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a drill press according to the presentinvention,

FIG. 2 is a left side elevational view of a drill press table assemblyforming part of the drill press shown in FIG. 1.

FIG. 3 is a perspective view showing components of the table assembly ofFIG. 2.

FIG. 4 is a side elevational view of a fence and clamp assembly formingpart of the drill press according to the invention.

FIG. 5 is a right side elevational view of the drill press tableassembly shown in FIG. 2.

FIG. 6 is a left side elevational view of a second embodiment of a drillpress table assembly forming part of the drill press shown in FIG. 1.

FIG. 7 is a front elevational view of the drill press table assemblyshown in FIG. 2.

FIG. 8 is an overhead plan view of the drill press shown in FIG. 2.

FIG. 8A is a close-up overhead view, partially in section, of a portionof the drill press shown in FIG. 8.

FIG. 9 is a perspective view showing a corner portion of the tableassembly of FIG. 2.

FIG. 10A is a cross-sectional view of the corner portion shown in FIG.9.

FIG. 10B is a side elevational view of the corner portion shown in FIG.9.

FIG. 11A is a perspective view showing a third embodiment of a drillpress table assembly forming part of the drill press shown in FIG. 1.

FIG. 11B is a close-up perspective view showing a corner portion of thedrill press table assembly of FIG. 11A.

FIG. 12 is a perspective view showing a router attachment table formingpart of the drill press shown in FIG. 1.

FIG. 13 is a front elevational view showing the router attachment tableof FIG. 12.

FIG. 14 is a top plan view of a sliding fence assembly forming part ofthe drill press shown in FIG. 1.

FIG. 15 is a front elevation view of the fence assembly shown in FIG.14.

FIG. 16 is a right side elevational view of the fence assembly shown inFIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 and 2, drill press 1 includes main supportpost 3, base 5 and head 7. Support post 3 may have a hollow cylindricalshape and fits within an opening formed in base 5 and is supported bybase 5 to extend vertically. Head 7 includes an opening which receivespost 3 and is supported thereby. A conventional chuck and rotatablehandle for raising or lowering the chuck extend from head 7 and do notform part of the invention. Similarly, a conventional drive mechanismfor the chuck is disposed within head 7 and does not form part of theinvention. Cylindrical casting 4 is disposed about support post 3 andcircular plate 6 is fixedly secured to casting 4. Table assembly 10 issecured to circular plate 6. Circular plate 6 includes central opening6a formed therethrough and pointer 6b (FIG. 8) disposed generally at theuppermost point on the circumference.

With further reference to FIGS. 2, 3, 5 and 7, table assembly 10 furtherincludes table 11 which is secured to pivot assembly 20. Table 11 has areduced thickness at the left and right front corners so as to formgenerally square cut-out regions 11a. Clamp plates 12 are removablydisposed in cut-out regions 11a, as described further below. Tableassembly 10 further includes rectangular brackets 19 which extenddownwardly from the lower surface of table 11. Brackets 19 include twoholes 19a and extends forwardly from the rear of table 11 to atermination point just to the rear of cut-out regions 11a.

Table 11 further includes two slots 13 formed in the upper surface.Slots 13 extend from front to rear of table 11 and have a T-shapedcross-section formed by opposite, overhanging lips 13a. A plurality ofcircular vertical openings 14 are formed through the upper surface oftable 11. Preferably, openings 14 extend entirely through the width oftable 11. A plurality of horizontal circular channels 48 are formedwithin table 11 so as to extend substantially parallel to the uppersurface of the table. Two pairs of channels 48 are formed through thefront end surface of table 11 and extend to the rear end surface of thetable. Similarly shaped pairs of channels 50 extend from one side oftable 11 towards the other side, generally perpendicular to channels 48.As shown in FIG. 8, the pair of channels 50 which begins on the leftside of the table is offset from the pair of channels 50 which extendsfrom the right side of the table. The function and structure of slots 13and channels 48 and 50 are described in greater detail below.

Pivot assembly 20 further includes wishbone table assembly support(wishbone) 22 having center arm 24, and forwardly extending side arms28. Center arm 24 includes circular portion 24a having central hole 24band arc-shaped opening 24c formed therethrough. Locking clamp 25 isdisposed through arc-shaped opening 24c. Locking clamp 26 is aconventional adjustable handle, and includes a cylindrical base, ahandle portion extending obliquely from one end of the base, and ascrew-threaded extension extending axially from the other end of thebase. The screw-threaded end is disposed in correspondingscrew-threading in circular plate 6. A washer is disposed about thescrew-threaded end and frictionally engages the surface of wishbone 22at the location of arcuate opening 24c when clamp 25 is tightened. Sidearms 26 include forward ends 27 having upper and lower holes 27a and27b. Forward ends 27 have a slightly greater vertical dimension than theremaining portions of side arms 26. Wishbone 22 is secured to circularplate 6 by pivot pin 23 disposed through central hole 24b and hole 6aformed in plate 6. Circular portion 24a includes scale 24d formed on theupper circumference.

When locking clamp 25 is rotated so as to loosen the engagement of thewasher on circular portion 24a, wishbone 22 may be rotated about pivotpin 23 and thus about a horizontal axis which is generally perpendicularto the planes of plate 6 and circular portion 24a. The screw-threadedextension of clamp 25 slides within arcuate opening 24c during rotation.Since, as described further below, table 11 is secured to wishbone 22,table 11 also is pivoted about this axis. The degree of rotation withrespect to the vertical of wishbone 22 is shown by pointer 6b on scale24d. In particular, pointer 6b indicates the degree of rotation of table11 with respect to a vertical of plane which is perpendicular to thefront and rear of the table. In other words, the scale indicates thedegree of side to side rotation of table 11. Locking clamp 25 istightened to secure wishbone 22 in the desired position.

Pivot assembly 20 further includes trunnions 30 having a semi-ovalshape. Each trunnion 30 includes upper through holes 30a, central pivothole 30b, and arcuate slot 30c formed through the lower periphery.Trunnions 30 are secured for pivoting motion, outwardly of each side arm26 of wishbone 22, by pivot pins 31 disposed through pivot holes 30b andupper holes 27a. Conventional adjustable locking clamp 32 having thesame structure as described for locking clamp 25 has a screw-threadedend disposed through arcuate slot 30c of each trunnion 30, and extendinginto screw-threaded lower holes 27b. Locking clamps 32 include washerelements 32a disposed adjacent the surface of trunnions 30. Clamps 32may be tightened by rotation to force the washers into frictionalengagement against the trunnions and securely clamp the trunnionsagainst side arms 26 of wishbone 22, to thereby preclude the trunnionsfrom pivoting relative to wishbone 22. Alternatively, clamps 32 may berotated to release the frictional engagement and thereby allow trunnions30 to pivot relative to side arms 26. During such pivoting of trunnions30, arcuate slots 30c move along the locations where clamps 32 extendtherethrough.

Screws 34 extend through upper through holes 30a in trunnions 30 andcorresponding holes 19a in brackets 19. Nuts 36 are disposed on theextending ends of screws 34 and thereby secure each side of table 11 toone trunnion 30. Table 11 may be pivoted from a generally horizontalposition as shown FIGS. 2 and 5, about a horizontal axis parallel to thefront and rear ends of the table, to a position in which the table isinclined forwardly downwardly with respect to the user, as shown inFIGS. 1 and 11a. Table 11 is allowed to pivot by loosening clamps 32 asdescribed above to allow pivoting of trunnions 30, and is fixed in anydesired angle by re-tightening the clamps. In a preferred embodiment,table 11 may pivot or tilt between at least 0° and 45° relative to avertical plane which extends substantially parallel to the front andrear edges of the table. Trunnions 30 may also include scale 36 formedalong arcuate slots 30c to show the pivot angle at which table 11 hasbeen fixed.

With further reference to FIGS. 1, 2, 5, and 7, trunnions 30 also mayinclude locking pins 38 which fit through an opening formed in thetrunnions. Locking pins 38 include a protrusion which extends throughtrunnions 30 and into one of a plurality of holes 39 formed through sidearms 26 at various locations along an arc which is centered about pivotholes 30b, that is, along an arc traversed by arcuate slots 30c whentrunnions 30 are pivoted. The locations of holes 39 correspond topredetermined preferred pivot angles for table 11. Locking pins 38 arebiased, for example, by spring biasing such that the protrusions extendthrough holes 39 to thereby lock trunnions 30 at one of thepredetermined pivot angles. In order to adjust the pivot angle of table11, locking pins 38 are pulled outwardly against the spring bias toremove the protrusions from holes 39 and thereby allow trunnions 30 topivot. After a desired predetermined pivot angle is reached, lockingpins 38 are released. If table 11 has been pivoted to one of thepredetermined pivot angles, the protrusions will extend through thecorresponding holes 39 and help secure trunnions 30 at the desiredangle. If table 11 has not been pivoted to a predetermined pivot angle,the locking pin protrusions will simply rest against the surface of arms28. In either case, locking clamp 32 will be re-tightened to securetable 11 in the desired position.

With reference to FIG. 6, a second embodiment of the table assembly isshown as table assembly 10'. Assembly 10' includes table 11' whichincludes brackets 19' having elongated slots 19a', instead of holes 19aas in table 11. Slots 19a' allow the horizontal position of table 11' tobe adjusted relative to trunnions 30. In particular, the horizontalposition may be adjusted by loosening nuts 36, and pulling or pushingtable 11' to be adjusted relative to trunnions 30. In particular, thehorizontal position may be adjusted by loosening nuts 36, and pulling orpushing table 11' to a desired position with screws 34 sliding in slots19a'. The nuts are re-tightened to secure table 11' in the desiredposition. Accordingly, table 11' may be moved away from or towardssupport post 3. In all other respects, table assembly 10' is identicalto table assembly 10.

With further reference to FIGS. 5-8A, a vertical height adjustmentmechanism for table 11 is shown. The mechanism includes cylindricalcasting 4 which is secured about support post 3. Casting 4 is split atthe rear to form two "halves" which each include rearwardly extendingclamping projection 4c having screw-threaded openings. Clamp arm 4dincludes a screw-threaded projection which extends into thescrew-threaded openings of claiming projections 4c. By rotating clamparm 4d, projections 4c may be forced apart to thereby loosen theengagement of each "half" of casting 4 about support post 3. Casting 4is then free to move along support post 3.

Casting 4 further includes height adjustment housing 4a having aconventional pinion gear (not shown) disposed therein and rotatableangle 4b linked to the pinion gear. The pinion gear meshes with rack 3awhich extends along the length of support post 3 and is secured at thetop within collar 3e and at the bottom by an upwardly extending portion5a of base 5 so as to be freely rotatable about post 3. When handle 4band thus the pinion gear are rotated, the gear moves along rack 3a tothereby raise or lower casting 4 along support post 3 to adjust thevertical position of wishbone 22 relative to support post 3. Thus thevertical position of table 11 may be adjusted. When table 11 is in itsdesired vertical position, clamp arm 4d is rotated to tightenprojections 4c and secure casting 4 and thus table 11.

As described above, rack 3a is freely rotatable about support post 3.Accordingly, when casting 4 is loosened by rotation of handle 4d, thecasting may be freely rotated about post 3, with the pinion gearremaining in mesh with rack 3a and causing the rack to rotate about post3. This rotatability of casting 4 allows table 11 to be pivoted about avertical axis defined by post 3. With reference to FIG. 8A, support post3 includes centrally located, vertically extending front notch 3b. Notch3b is formed directly to the rear of the center of the drill chuck.Casting 4 includes rectangular notch 4e formed on the interiorcylindrical surface. Notch 4e is located on a horizontal axis whichextends through the center of table 22. Spring 3d is disposed in notch4e and biases ball bearing 3c outwardly from notch 4e. When casting 4and table 11 are rotated, ball bearing 3c is forced out of notch 3bagainst the spring bias. Ball bearing 3c is forced into notch 4e andrides along the surface of support post 3 during rotation. Afterrotation, when it is desired to re-center table 11 under the drillchuck, the table and casting 4 are rotated until notch 4e is oppositenotch 3b. When the center location is reached, spring 3d biases ballbearing 3c back into notch 3b. Since the ball bearing and notchesprovide some resistance to rotation of casting 4, this arrangementidentifies when table 11 has reached the center location. Thereafter,handle 4d is rotated to secure casting 4 and table 11 against furtherrotation.

As described above, the present invention provides a drill press inwhich the position of the table may be adjusted in four ways. Table 11may be pivoted towards the user about a horizontal axis parallel to thefront edge, or from side-to-side about a horizontal axis parallel to theside edges. The vertical height of the table also can be adjusted, andthe table may be pivoted about a vertical axis. By making use of thesefour degrees of movement, a user may position the table and thus aworkpiece in an optimum position.

With further reference to FIGS. 1 and 7-10B, telescoping extension armassembly 40 forming part of the invention is disclosed. Assembly 40includes clamp plates 12 disposed in cut-out regions 11a as describedabove, and telescoping extension arm 42. Extension arm 42 may be clampedby clamp plates 12 in any one of six positions extending outwardly fromtable 11 to provide support for the extending portion of a workpiece.Extension arm 42 includes a pair of cylindrical or tubular extensionrails 44 and support plate 46 secured to the ends of rails 44 by a pairof nuts. Support plate 46 has an overall rectangular shape.

As described above, table assembly 10 includes two pair of horizontalchannels 48 extending substantially parallel to the side edges of table11 from the front and back edges of the table. Table assembly 10 alsoincludes two pair of horizontal, generally circular channels 50extending substantially parallel to the front edge of table 11 from theleft and right edges of the table. Channels 48 and 50 have asubstantially circular cross-section. With specific reference to FIGS.6, 7 and 9, the laterally inner channel 48 of each pair is formedentirely within table 11. However, the outer channel 48 of each pair isformed by semi-circular openings disposed in the lower surface of table11 at the locations of cut-out portions 11a and correspondingsemi-circular openings formed in the upper surface of clamp plates 12.Similarly, the rear channel 50 of each pair is formed entirely withintable 11, while the forward channel 50 of each pair is formed byopenings in both table 11 and clamp plate 12. The diameter of channels48 and 50 is substantially the same as the diameter of extension rails44.

Vertical through holes 52 are formed in clamp plates 12 andcorresponding screw-threaded openings 54 are formed in the lower surfaceof table 11. Holes 52 and opening 54 are offset from channels 48 and 50.Clamps 56 have screw-threaded ends 58 which are disposed through holes52 and into openings 54 to adjustably secure clamp plates 12 withincut-out portions 11a. Clamps 56 may be rotated so as to loosely holdclamp plates 12 against the lower surface of table 11. Alternatively,clamps 56 may be tightened to securely hold clamp plates 12 against thelower surface of table 11. Support plate 46 is positioned outwardly oftable 11 by inserting rails 44 within one pair of channels 48 or 50 whenclamp plates 12 are only loosely held against table 11. When supportplate 46 is positioned at any desired location relative to the edge oftable 11, clamp 56 is then tightened to securely hold clamp plates 12against the lower surface of table 11, thereby locking one extensionrail 44 of arm 42 within the channel which is formed jointly by table 11and clamp 12.

Support plate 46 provides support for the extending portion of workpiece100 as shown in FIG. 10b. Channels 48 open on both the left and rightsides at the front and rear of table 11, and channels 50 open on theleft and right edges of table 11. Thus, support plate 46 can bepositioned outwardly of either the left or right edge of table 11, asshown in FIGS. 7 and 8. Alternatively, as shown in FIGS. 8 and 10a,support plate 46 can be positioned in front of or behind table 11 oneither the right or left side. Furthermore, two extension arms 42 can besecured to table 11 at any time. In particular, since channels 50extending from the left side of table 11 are offset from channels 50extending from the right side, each extension arm 42 may be inserted inone pair of channels 50 so as to allow plates 46 to extend from theopposite sides of table 11, as shown in FIG. 8. Alternatively, one arm42 can be inserted in each pair of channels 48 so as to provide plates46 extending from each side of the front or back of table 11.Accordingly, either the effective width or the effective length of table11 may be increased.

With reference to FIGS. 11A and 11B, a second embodiment of thetelescoping extension arm assembly is shown. Telescoping assembly 40'includes table 111 and clamp plates 112 in which both channels of eachpair of channels 48 and 50 are formed by semi-circular openings disposedin the lower surface of table 111 at the locations of cut-out portions11a and corresponding semi-circular openings formed in the upper surfaceof clamp plates 112. Thus, both rails 44 of extension arms 42 we clampedbetween table 111 and plates 112. In all other respects, assembly 40' isidentical to assembly 40.

Through the telescoping extension arm assembly has been described asincluding clamp plates 12 and 112 which fit within cutout portions oftable 11 and 111, it is understood that telescoping extension arms 42may be clamped in other ways. For example, table 11 need not includecutout regions and may have a substantially constant cross section.Rails 44 may include a plurality of through holes which may be lined-upwith screw-threaded through holes formed directly in the table. Thescrew-threaded end of the locking clamp would extend through the holesof rails 44 within table 11 to secure the rails at a desired location.Furthermore, though holes 48 and 50 and rails 44 have been described ascircular, other shapes could be used as well. For example, the holes andrails could have a rectangular or square cross section.

With further reference to FIGS. 4 and 14-16, a sliding guide fence andvertical clamp assembly are shown. Sliding guide fence 70 includesvertical fence wall 72 having a flat rear surface and integrally formedlower guide rail 72a which extends downwardly from fence wall 72. Guiderail 72a has a rectangular cross-section and extends from just in frontof wall 72 to a termination point to the rear of wall 72. Handle mount76 also is integrally formed with wall 72 and has a semi-oval shape.Mount 76 extends from the front of wall 72, at a location above guiderail 72a. Through hole 76a extends through mount 76 and guide rail 72a.Bolt 74 is square or rectangular and includes screw-threaded opening74a. Bolt 74 is disposed below guide rail 72a such that opening 74a iscoincident with opening 76a. Guide rail 72a and bolt 74 jointly have aT-shaped cross-section generally corresponding to the cross-section ofT-shaped slots 13 of table 11. In particular, the width of guide rail72a is about the same as the distance between opposite overhanging lips13a and the width of bolt 74 is about the same as the width of slots 13below lips 13a.

Handle 78 is conventional and includes shaft 78b having a screw-threadedlower end which extends through opening 76a and into screw-threadedopening 74a of bolt 74. Handle 78 further includes cylindrical support78a, and handle arm 78c integrally formed with and extending fromsupport 78a. Support 78a is disposed about shaft 78b such that when arm78c and support 78a are raised, support 78a may rotate relative to shaft78b, thereby allowing the position of arm 78c relative to wall 72 to beadjusted. However, when arm 78c and support 78a are lowered, rotation ofarm 78c and support 78a causes rotation of shaft 78b.

In order to secure guide fence 70 at a desired location on table 11,guide rail 72a and loosened bolt 74 are slidingly received in one ofT-shaped slots 13. Accordingly, fence wall 72 of guide fence 70 may bepositioned at any location from the front to the rear edge of table 11.When the desired location is reached handle arm 78c and support 78a arerotated while in the lower position, thereby causing rotation ofscrew-threaded shaft 78b. Since bolt 74 has generally the same width asslot 13 below lips 13a and a greater width than the distance betweenlips 13a, bolt 74 is constrained from rotation, and is instead raisedupwardly towards the lower surface of guide rail 72a and overhanginglips 13a of slot 13. Bolt 74 is brought into tight frictional engagementwith lips 13a to thereby secure guide fence 70 at the desired location.By rotation of handle arm 78c in the opposite direction, bolt 74 may beloosened, allowing guide fence 70 to be moved along the surface of table11, or removed entirely from table 12.

Guide fence 70 further includes two vertically extending cylindricalholes 71. Holes 71 are disposed on opposite sides of mount 76, and areformed partially within the plane of wall 72 and partially withinsemi-cylinders 73 which extend outwardly from the front face of wall 72.Overhanging flats 75 are disposed within holes 72, and project inwardlyfrom one side. With reference to FIG. 4, clamps 80 may be disposedwithin holes 71. Clamps 80 include support arm 82 having upperhorizontal portion 82b and vertical pole portion 82a extendingdownwardly from one end of portion 82b. Pole portion 82a is cylindricaland at the lower end has a decreasing diameter which expands into knob82c. Knob 82c has an upper projecting lip which extends partially aroundthe upper circumference. Pole 82a fits within hole 71 and is securedtherein by rotating the upper projection lip so as to engage beneathflat 75. Clamps 80 also include screw-threaded shaft 84 which fitswithin a corresponding screw-threaded opening in upper horizontalportion 82b. Clamp disc 86 is secured at the lower end of shaft 84. Byrotating shaft 84, clamp disc 86 may be raised or lowered.

As discussed, guide fence 70 may be slided along either one of guideslots 13 and then locked in the desired location. Wall 72 of fence 70provides support for one side of a workpiece to help maintain theposition during operation of the drill press. The position of theworkpiece can be further secured by use of clamp 80 which is inserted inguide fence 70 with knob 82c secured under flat 75. Clamp plate 86 isthen lowered into contact with a workpiece to secure the position.Alternatively, clamps 80 may be disposed directly within holes 14disposed through the upper surface of table 11, at various locations.Holes 14 include flats or lips 14a under which knobs 82c would bedisposed to secure clamps 80 in place.

With reference to FIGS. 1, 3, 12 and 13, a removable inner table androuter attachment is shown. Table 11 includes a square center openinghaving inwardly projecting ledges 92 around the periphery. Inner table90 is removably disposed in the opening and rests upon ledges 92. Thisremovability of inner table 90 allows the table to be replaced when wornout due to use of the drill press, without requiring that the entiretable 11 be replaced. Since the center portion of the table is mostlikely to ear out under long-term use, the provision of a removablecenter table insert provides for economical maintenance of the drillpress.

With further reference to FIGS. 8, 12 and 13, inner table 90 includescenter circular opening 94, and four small screw openings 96 disposedabout center opening 94. Screw openings 96 are disposed generallyequidistant along the periphery of a circle having opening 94 at thecenter. Conventionally operating router 110 includes router bit 102extending through an opening in disc 112 secured to the lower surface ofthe router. Disc 112 includes a plurality of screw-threaded holes 114formed at locations which correspond to the locations of screw holes 96in inner table 90. Router 110 is inverted and removably secured to innertable 90 by a plurality of screws 98 disposed through holes 96 and 114,with router bit 102 extending through circular opening 94. Accordingly,the chuck of a drill press according to the present invention may alsobe used to hold a guide pin as in a conventional pin router. As shown inFIG. 13, router bit 102 will be axially aligned with the guide pin.Alternatively, if it is desired to have the router bit off-center withrespect to the guide pin, such off-centering can be obtained by pivotingtable 11 about the vertical axis defined by support post 3, as describedabove. Though inner table 90 is shown as including provisions for arouter attachment, table 90 also can be provided without such anattachment.

We claim:
 1. A machine tool comprising:a vertical post; a tablesupported by said vertical post; a telescoping extension arm, said armfixably securable at selected locations relative to said table by saidclamp plate; said table and said clamp plate jointly defining a channel,said telescoping extension arm including an extension rail, wherein saidrail is slidably disposable within said channel and may be clampedbetween said clamp plate and said table to fixably secure said arm. 2.The machine tool recited in claim 1, said table defined by upper andlower surfaces and sides and ends, said table having a reduced thicknessat a corner to form a cut-out region, said clamp plate fitting withinsaid cut-out region, said table including an opening extending from oneof the side and ends of the table, said clamp plate including acorresponding opening such that when said clamp plate is located in saidcut-out region, said openings jointly define a portion of said channelwith said channel extending between the upper and lower surfaces.
 3. Themachine tool recited in claim 2, said table further including a secondchannel formed entirely within said table, said arm including a secondextension rail, wherein,said second extension rail is slidablydisposable within said second channel.
 4. The tool of claim 3, whereinthe second channel has a circular cross-section.
 5. The tool recited inclaim 1, said table and said clamp plate jointly defining a secondchannel extending between the upper and lower surfaces, said secondchannel extending substantially perpendicular to said first channel,wherein,said rail is slidably disposable within said second channel andmay be clamped between said clamp plate and said table.
 6. The tool ofclaim 5, wherein the second channel has a circular cross-section.
 7. Thetool of claim 1, wherein said channel has a circular cross-section. 8.The tool recited in claim 1, said table including a screw-threadedopening, said clamp plate including a vertical through hole formed at alocation corresponding to said screw-threaded opening, said tool furtherincluding a clamp having a screw-threaded end which may be disposedthrough said through hole and into said screw-threaded opening toadjustably secure said clamp plate to said table.
 9. The tool recited inclaim 1, wherein, said tool is a drill press and further comprises:ahead supported by said post at a location above said table; a rotatablechuck supported by said head; drive means for rotating the chuck; andmeans for raising and lowering the chuck relative to said table.
 10. Themachine tool recited in claim 7, whereinsaid table has an upper surface;the tool further comprising a guide fence slidably disposable along saidupper surface of said table and securable at selectable locations. 11.The machine tool recited in claim 10, said table including a slotextending along said upper surface, said guide fence including a guiderail, said guide rail slidably fitting within said slot.
 12. The machinetool recited in claim 11, said guide rail including an opening, saidguide fence including a bolt having a screw-threaded opening, said boltdisposed below said guide rail within said slot and with said boltopening coincident with said rail opening, said guide fence furtherincluding a screw-threaded shaft extending through said rail opening andinto said bolt opening, said slot having overhanging lips, wherein, whensaid shaft is rotated in a first direction, said bolt is raised towardssaid lips to secure said guide fence at a selected location, and whensaid shaft is rotated is a second direction, said bolt is lowered awayfrom said lops to allow said guide fence to be slided along said slot.13. The tool recited in claim 10, wherein, said tool is a drill pressand further comprises:a head supported by said post at a location abovesaid table; a rotatable chuck supported by said head; drive means forrotating the chuck; and means for raising and lowering the chuckrelative to said table.
 14. The tool recited in claim 10, said guidefence including a vertically extending cylindrical hole, said toolfurther comprising a clamp removably disposable within said hole, saidclamp including a vertically movable clamping element which may belowered to secure a workpiece against said table and which may be raisedto release a workpiece.
 15. The machine tool recited in claim 7,whereinsaid table has an upper surface, said upper surface comprising aplurality of holes; and the tool further comprising a clamp comprising asupport arm removably disposable within said holes to removably securesaid clamp to said table, and a vertically movable clamping elementwhich may be lowered to secure a workpiece against said table and whichmay be raised to release a workpiece.
 16. The tool recited in claim 15,wherein, said tool is a drill press and further comprises:a headsupported by said post at a location above said table; a rotatable chucksupported by said head; drive means for rotating the chuck; and meansfor raising and lowering the chuck relative to said table.
 17. A machinetool comprising:a vertical post; a table supported by said verticalpost; a clamp plate adjustably secured to said table; a telescopingextension arm fixably securable at selected locations relative to saidtable by said clamp plate, the telescoping extension arm comprisingfirst and second extension rails; wherein said table and said clampplate jointly define a first channel receiving the first extension rail.18. The tool of claim 17, wherein the first extension rail is clampedbetween the clamp plate and the table.
 19. The tool of claim 17, whereinthe first channel has a circular cross-section.
 20. The tool of claim17, wherein the first extension rail is clamped between the clamp plateand the table.
 21. The tool of claim 17, wherein said table and saidclamp plate jointly define a second channel receiving the secondextension rail.
 22. The tool of claim 21, wherein the second extensionrail is clamped between the clamp plate and the table.
 23. The tool ofclaim 21, wherein the second channel has a circular cross-section. 24.The tool of claim 17, wherein the second extension rail is clampedbetween the clamp plate and the table.
 25. The tool of claim 17, whereinthe table defines a second channel receiving the second extension rail.26. The tool of claim 25, wherein the second channel has a circularcross-section.
 27. The tool of claim 17, wherein said tool is a drillpress, and further comprises:a head supported by said post at a locationabove said table; a rotatable chuck supported by said head; drive meansfor rotating the chuck; and means for raising and lowering the chuckrelative to said table.
 28. A machine tool comprising:a vertical post; atable supported by said vertical post, said table being defined by upperand lower surfaces and sides and ends, said table having a reducedthickness area to form a cut-out region; a clamp plate adjustablysecured to said table and fitting within said cut-out region; and atelescoping extension arm fixably securable at selected locationsrelative to said table by said clamp plate.
 29. The tool of claim 28,wherein the telescoping extension arm comprises a first extension rail.30. The tool of claim 29, wherein at least one opening is disposed in atleast one of said clamp plate and table, said at least one openingdefining a first channel for receiving the first telescoping extensionrail.
 31. The tool of claim 30, wherein said at least one opening has asemi-circular cross-section.
 32. The tool of claim 30, wherein the firstchannel has a circular cross-section.
 33. The tool of claim 30, whereinsaid at least one opening extends from one of the side and ends of thetable.
 34. The tool of claim 33, wherein a second opening extends acrossthe clamp plate, so that both openings jointly define the first channel.35. The tool of claim 28, wherein at least one opening is disposed in atleast one of said clamp plate and table, said opening defining a firstchannel for receiving the telescoping extension arm.
 36. The tool ofclaim 35, wherein said at least one opening has a semi-circularcross-section.
 37. The tool of claim 35, wherein the first channel has acircular cross-section.
 38. The tool of claim 35, wherein said at leastone opening extends from one of the side and ends of the table.
 39. Thetool of claim 38, wherein a second opening extends across the clampplate, so that both openings jointly define the first channel.
 40. Thetool of claim 28, wherein said tool is a drill press, and furthercomprises:a head supported by said post at a location above said table;a rotatable chuck supported by said head; drive means for rotating thechuck; and means for raising and lowering the chuck relative to saidtable.